Detailed Description

Implements the 3-valued theorem used for the user assertions and the result of query. It is simply a wrapper around class Theorem, but has a different semantic meaning: the formula may have partial functions and has the Kleene's 3-valued interpretation. The fact that a Theorem3 value is derived means that the TCCs for the formula and all of its assumptions are valid in the current context, and the proofs of TCCs contribute to the set of assumptions.